point in time backup with parallel mariadb-dump --dir

Is there a way to take a point in time backup when using:

mariadb-dump --lock-tables --all-databases --dir=/dumpdir --parallel=4

e.g. combining the above with:

--master-data=2 --dump-slave=2 --gtid

and if so, where would I find the binlog file and pos or the gtid value? Afiak it is not documented.

it would be great if an info file could be generated analog to mariadb-backup but I could not find it.

Also my guess is --single-transaction would be incompatible with parallel selects, hence the --lock-tables in above statement, but this is nog documented.